package day2018_lab02.Test02;

public class Cirlie {
    //圆形类属性

    int r;
    double PI= Math.PI;
    //行为
    public double length(){
        return PI*2*r;
    }
    public double area(){
        return PI*r*r;
    }
    public String toString(){
        return "周长"+length()+"面积"+area();
    }
}
